In the bag forming, closing, and handling art, it is known to apply a bendable and flexible strip across a bag top to assist in holding filled bags closed, and especially for use in reclosing bags to preserve the contents thereof after initial opening. See U.S. Pat. Nos. 3,315,877 and 3,024,962. Such strips are commonly designated as tin ties and normally comprise one or more lengths of bendable metal, such as aluminum or copper, contained within a sheath of plastic or paper material molded or sealed over the metal. As is disclosed in U.S. Pat. No. 3,315,877, the tin tie strip is affixed atop bag tops so as to provide bendable end segments freely extending beyond the bag side edges. These end segments may be bent around the bag top to hold the bag top folded closed both upon bag filling and by the user after the bag is opened.
U.S. Pat. No. 3,719,318 discloses the application of a tin tie strip to a polyethylene bag by heat sealing a film projection of the tin tie strip to a face of the bag in a separate, bag-forming operation prior to filling and closing the bag. In the course of the closing of the bag after filling, the top of the bag is rolled over and the ends of the tin tie are mechanically bent under the rolled, closed bag top within tucks formed in the end walls of the bag top.
The use of adhesive applied to the outside face of a bag wall to secure multiple folds of a closure at one end of the bag is disclosed in the aforesaid U.S. Pat. No. 3,315,877 as well as in U.S. Pat. No. 2,429,505.
Although the usefullness of tin tie strips in securing reclosable bags is well established, the packaging industry is lacking in a simple and effective way to apply tin tie strips to bag tops in the course of bag closing operations on a fully mechanized, high speed basis. It is with that need in mind that the improved machine and process disclosed herein have been developed.